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A154655
Number of permutations of length n within distance 6.
6
1, 1, 2, 6, 24, 120, 720, 5040, 30960, 172200, 899064, 4553166, 22934774, 116914351, 610093513, 3222826972, 17101449940, 90706002192, 479654768640, 2527274267136, 13280313508416, 69734129749632, 366283822765632, 1925290900630896, 10126754515065868
OFFSET
0,3
COMMENTS
a(n) equals the permanent of the n X n matrix with 1's along the central thirteen diagonals, and 0's everywhere else. - John M. Campbell, Jul 10 2011
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..1000 (terms n=1..400 from R. H. Hardin)
Torleiv Kløve, Spheres of Permutations under the Infinity Norm - Permutations with limited displacement, Reports in Informatics, Department of Informatics, University of Bergen, Norway, no. 376, November 2008.
FORMULA
G.f. is a rational function f(x)/g(x) where f has degree 482 and g has degree 494.
CROSSREFS
Column k=6 of A306209.
Sequence in context: A045977 A177278 A173847 * A256181 A293784 A179348
KEYWORD
nonn,easy
AUTHOR
Torleiv Kløve, Jan 13 2009
EXTENSIONS
a(0)=1 prepended by Alois P. Heinz, Jan 28 2019
STATUS
approved